Progress and Perspectives in Designing Flexible Microsupercapacitors

Abstract

Miniaturized flexible microsupercapacitors (MSCs) that can be integrated into self-powered sensing systems, detecting networks, and implantable devices have shown great potential to perfect the stand-alone functional units owing to the robust security, continuously improved energy density, inherence high power density, and long service life. This review summarizes the recent progress made in the development of flexible MSCs and their application in integrated wearable electronics. To meet requirements for the scalable fabrication, minimization design, and easy integration of the flexible MSC, the typical assembled technologies consist of ink printing, photolithography, screen printing, laser etching, etc., are provided. Then the guidelines regarding the electrochemical performance improvement of the flexible MSC by materials design, devices construction, and electrolyte optimization are considered. The integrated prototypes of flexible MSC-powered systems, such as self-driven photodetection systems, wearable sweat monitoring units are also discussed. Finally, the future challenges and perspectives of flexible MSC are envisioned.

MXene-Based Micro-Supercapacitors: Ink Rheology, Microelectrode Design and Integrated System

“…11−14 In contrast, MSCs possess excellent cycle life (>100,000 cycles) and high power density (>10 mW cm −2 ), making them more promising for a wide range of applications. 12,15 However, their relatively low energy density (<0.1 mWh cm −2 ) often limits their application in integrated microelectronic systems. Therefore, the option of electrode materials with high conductivity and large charge storage capacity is crucial for highperformance micro-supercapacitors.…”

“…With the increasing demand for portable and multifunctional electronic devices, energy storage devices tend to be miniaturized, lightweight, and integratable. − Microbatteries (MBs) and micro-supercapacitors (MSCs) are two complementary microenergy storage devices that have received wide attention. − Although MBs are popular microenergy devices due to their high energy density (1 mWh cm –2 ), their limited cycle life (up to 500 to 10,000 cycles) means that they require frequent maintenance and replacement, and low power density (<5 mW cm –2 ) limits their application at high currents. − In contrast, MSCs possess excellent cycle life (>100,000 cycles) and high power density (>10 mW cm –2 ), making them more promising for a wide range of applications. , However, their relatively low energy density (<0.1 mWh cm –2 ) often limits their application in integrated microelectronic systems. Therefore, the option of electrode materials with high conductivity and large charge storage capacity is crucial for high-performance micro-supercapacitors.…”

Screen-Printed Wearable Sweat Sensor for Cost-Effective Assessment of Human Hydration Status through Potassium and Sodium Ion Detection

“…The advent of the big data era and the application of artificial intelligence methods hold promise for accelerating this research; however, the scarcity of sufficient data remains a significant challenge. Although several researchers have explored the feasibility of using sweat potassium and sodium ion concentrations to assess human hydration status, the existing methods primarily rely on photolithography for fabricating the necessary electrodes [ 23 , 24 , 25 ]. While these electrodes offer exceptional accuracy and detection performance, their high fabrication costs restrict their widespread utilization, hindering the collection of extensive medical data.…”

Laser-Assisted Patterning of Co–Ni Alloy/Reduced Graphene Oxide Composite for Enhanced Micro-supercapacitor Performance

“…Laser-assisted fabrication has been studied widely because it allows the direct synthesis of nanomaterials into microscale patterns without a photomask and can be applied in supercapacitors, batteries, and electrocatalysts . In particular, the site-specific reduction of GO to highly conductive rGO has been used to fabricate flexible MSCs because of the local photothermal reaction under IR laser irradiation. , A previous study developed a laser-assisted ZnO nanorod (NR)/rGO patterning method . However, the previous technique required the post-hydrothermal growth of the ZnO NRs after a laser-assisted ZnO seed formation process.…”

“…7 In particular, the site-specific reduction of GO to highly conductive rGO has been used to fabricate flexible MSCs because of the local photothermal reaction under IR laser irradiation. 8,9 A previous study developed a laser-assisted ZnO nanorod (NR)/rGO patterning method. 10 However, the previous technique required the post-hydrothermal growth of the ZnO NRs after a laser-assisted ZnO seed formation process.…”